How do I permanently add materials to Blender using Cycles?
Append imports the materials into you current scene, so it is project related. Yes, you will have to append them every time this way.

The solution I'd use in this situation is to append them to the default scene and save the edited default scene as the new default startup file (google how to do this, its easy). When you start Blender, the scene will be loaded with the added materials.

Make sure that you make the materials persistent by hitting the "F" button. Blender deletes unused materials on close if they are not persistent. The button will add a "fake user" and the material won't get deleted.

Here some post that could help you out:

Changing startup file

About the "F" and the "2" button in material panel